(a) Field of the Invention
The present invention relates to a contact structure of conductive films and a thin film transistor array panels including the same.
(b) Description of Related Art
Recently, information processing devices are rapidly developed to have various shapes, various functions, increasing processing speeds. The information processed by the information processing devices has a form of electrical signals and a display device is required as an interface between the processed information and users such that the users' eyes can see the processed information.
A liquid crystal display (LCD) as a representative of flat panel displays are promising since they are light, small, low-power-consumptive, and pro-environmental compared with a cathode ray tube (CRT) and they can realize high resolution and full color display.
The LCD converts the change of optical properties such as birefringence, optical rotatory power, dichroism, and light scattering into the visual change, and the change of the optical properties is obtained by the change of orientations of liquid crystal molecules by varying electric field applied thereto.
The LCD is driven in an active matrix type or a passive matrix type, and the former is used for a twisted-nematic (TN) mode LCD, etc., while the latter is used for a super-twisted nematic (STN) LCD.
The active matrix type driving requires switching elements such as thin film transistors (TFTs) for separately driving pixels, while the passive matrix type driving does not, and thus the active matrix type driving is relatively complicated.
A TFT includes a semiconductor layer such as amorphous silicon or polysilicon. Although the LCD including the polysilicon TFTs has low power consumption and low product cost, the polysilicon TFTs are made by relatively complicated manufacturing processes compared with the amorphous silicon TFTs. Accordingly, the polysilicon TFT LCD is usually used in small devices such as IMT-2000 mobile phones.
The amorphous silicon TFT LCD can realize a large screen and high productivity, and thus it is usually used in large devices such as notebook personal computers, desktop computers, and high definition television sets (HDTV).
However, the amorphous silicon TFT LCD may include flexible printed circuit films mounting driving circuit chips and attached to a liquid crystal panel and printed circuit boards (PCBs). This configuration places the amorphous silicon TFT LCD to a disadvantageous position in the cost and the slimness, which spoils the advantage of high productivity of the amorphous silicon TFT LCD.
In the meantime, the TFT LCD includes a plurality of conductors disposed on different layers, and the conductors are electrically connected via connection members. The contact between the conductors and the connection members may distort or delays signals due to the corrosion or the disconnection of the conductors.